Heat or air but not both
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Heat or air but not both
I have a 1999 Civic that my daughter drove while in college. The local mechanic would switch something to make either the heat or the air to work . If she switched it from heat to air it would switch but then it would not switch back .so which ever one he set it to she couldn't change it or it would not switch back. She took it to him 2 or 3 times just trying to get by till she graduated and got a new vehicle.I know it is probably going to be a pain to properly fix but if anyone can tell me what it is that needs replacing I would appreciate it.
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518 
Re: Heat or air but not both
Start at the water valve for the heater core.
See if the cable moves the lever about 90 degrees when you move the temp control from cold to hot.
If not, figure out why it doesn't.
See if the cable moves the lever about 90 degrees when you move the temp control from cold to hot.
If not, figure out why it doesn't.
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518 Re: Heat or air but not both
Is the cable housing (or sheath, the outer part of the cable) securely attached to the water valve? If it slips out of its holder then it won't push the lever for the valve.
Then follow the cable through the firewall to the bottom of the heater housing, get a flashlight, and see if the same issue is happening there where it attaches to the heater linkage.
Basically inspect both ends of the cable system to see where the problem lies.
Then follow the cable through the firewall to the bottom of the heater housing, get a flashlight, and see if the same issue is happening there where it attaches to the heater linkage.
Basically inspect both ends of the cable system to see where the problem lies.
